# What is the angle between #<-4,3,-8 ># and #< 1,-1,5>#?

##### 1 Answer

Oct 8, 2016

#### Explanation:

The dot product is used, because it has two definitions:

and

where

Compute the dot product, using the first definition:

Compute the magnitude of vector A:

Compute the magnitude of vector B:

Substitute the above into the second equation:

Solve for